Canada-wide gas boiler information · On-site service in Greater Vancouver, BC
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Comparison
Verdict in brief
The ALTA-080 and ALTA-120B are the two smallest heating-only Alta boilers, both 95.0% AFUE on the same 16.3 in-deep chassis with identical 2" venting. The 120B raises input from 8–80 to 13.6–120 MBH, heating capacity from 75 to 112 MBH and the net AHRI rating from 65 to 97 MBH, for 5 lb more weight (76 vs 71 lb).
Published manufacturer figures. Input and output are kept separate; blanks mean the manufacturer did not publish that value.
| Specification | Burnham Alta ALTA-080 | Burnham Alta ALTA-120B |
|---|---|---|
| Heating input, minimum | 8 MBH | 13.6 MBH |
| Heating input, maximum | 80 MBH | 120 MBH |
| Heating capacity | 75 MBH | 112 MBH |
| Net AHRI water rating | 65 MBH | 97 MBH |
| Efficiency (AFUE) | 95 % | 95 % |
| Vent size | 2 in | 2 in |
| Boiler weight | 71 lb | 76 lb |
| Boiler depth | 16.3 in | 16.3 in |
Both models are heating-only (not combis) at 95.0% AFUE on the OneTouch-controlled condensing platform with the 316L stainless steel heat exchanger, identical 2" CPVC/PVC or polypropylene venting and the compact 16.3 in boiler depth (dimension 'A').
The 120B exists for capacity: its 13.6–120 MBH heating input against the 080's 8–80 MBH prints 112 MBH heating capacity and a 97 MBH net AHRI water rating versus 75 and 65 MBH on the 080.
Physically the two are near twins — both connect on 1/2" NPT gas, run the Grundfos 26-99 circulator and carry the 50 psi MAWP with a 30 psi relief valve — with the 120B weighing 76 lb against the 080's 71 lb. Neither produces domestic hot water, so the choice follows a heat-loss calculation between roughly 75 and 112 MBH of required heating capacity.
Burnham
The Burnham Alta ALTA-080 is the smallest heating-only Alta: 8 to 80 MBH input at 95.0% AFUE with 75 MBH heating capacity and a 65 MBH net AHRI water rating, on the OneTouch-controlled wall-hung condensing chassis.
Burnham
The Burnham Alta ALTA-120B fires 13.6 to 120 MBH heating input at 95.0% AFUE — 112 MBH heating capacity and a 97 MBH net AHRI water rating — in the compact 16.3 in-deep heating-only Alta chassis.
Both are rated 95.0% AFUE per the Alta Product Data Sheet; efficiency does not separate them.
Input rises from 8–80 to 13.6–120 MBH, heating capacity from 75 to 112 MBH, net AHRI from 65 to 97 MBH, and boiler weight from 71 to 76 lb.
Yes — 2" universal vent connections for CPVC/PVC or polypropylene in a sealed-combustion direct-vent configuration.
A consultation includes a heat-loss review so the size is right the first time.
On-site service in Greater Vancouver, BC. ROMA lists “Open 7 days” on its site; call to confirm same-day availability.
Sources and verification
Facts checked September 9, 2026. Last updated September 9, 2026. Technical reviewer: not yet assigned.